According to molecular orbital theory,the number of unpaired electron$(s)$ in $O_{2}^{2-}$ is :

The number of species from the following which are paramagnetic and with bond order equal to $1$ is:
$H_2, He_2^{+}, O_2^{+}, N_2^{2-}, O_2^{2-}, F_2, Ne_2^{+}, B_2$

The diamagnetic species is

Arrange the following species in the correct order of their stabilities: $N_2^{-}, C_2, Ne_2, O_2^{2-}$

Compare the relative stability of the following species and indicate the magnetic properties: $O_2$,$O_2^+$,$O_2^-$ (superoxide),and $O_2^{2-}$ (peroxide).

Give the number of electrons in the species $H_2^+$,$H_2$,and $O_2^+$.